Automatic slack-adjuster.



C. 0. ANDERSON.

' AUTOMATIC SLACK ADIUSTER.

APPLICATION FILED SEPT. 5. IBI I.

Patented July 27, 1915.

III

@5; @Ma f atto-.meg l nnrrnp srarus rn'rnnr carica CHARLES 0. ANDERSON; OF QllflIAI-IA,` NEBRASKA,lA ASSIGNOR, BY MESNE ASSIGNMENTS, OIEt TWO-THIRIDS TO L.v D. lSIPlAUlLDINGr;

AUTOMATIC SLACIeADJUSTER.

Application led September 5, 1911.

To all 'whom ,it mayiconcem Be it? known that I, "CHARLES` O. Airman# son, acitizen of the UnitedStates', and a resident of Omaha, in the county of Douglas and State o-f Nebraska, have Vinvented cer#` tain new and useful .Improvements in` Automatic Slack-Adjusters, of" which the fol`4 lowing is a specification. j

My invention relates to slack adjusters for railwaybrake rig ing, and itjisv the ob'-,

` ject thereof-to provide a simple, inexpensive and'reliable device for automatically` compensating. in railway brakefriggingifor the are shown inthe accompanying'drawings, in

which# Figure 1isa=side'view,-partly sectional, of portions of the brake rigging with my automatic slack-'adjusting device applied thereto, Fig. 2 is a detail plan view of` the adjusting-sleeve rotatingdevice, and'Fig.' 3 is aview similar to Fig.f 1 and'showing a modified `form. of the-adjuster.

ln the construction shown the brakes are of the insidebungtypathe brake-beams 1 and 2 being hung betiveen'the wheels of the car-truck connected, respectively, withV the dead and 'livetrucliflevers 3 and 4. .The upper end of 'the 'dead-lever '3 is connected with the truck-frame 5 and theupper end of the live-lever 4 is connectedwith a rod 6 which is connected with thebrake-actuating. devices in the usual way. It will be under stood that the brake-beams may be support-` ed, and suppliedwith brake-shoes andrelease-springs in the ordinary manner.`

My invention provides means for auto# matically varying the length ofthebottonu` rod or truck-lever connection by whiclrthe lower ends of the dead and liveleversare connected with eachother, and inthe operation of the adjusting. means advantage is taken of thevariation 'in the angular relation ofthetrucklevers and bottom-rod'duri ing the movements of the `brakes' between the applied andrele'ase positions thereof. 'Referring toFig.` 1, the truck-lever connection comprises a head 7 connected with the lower end of thelive-lever 4, a 1'0d'8 Speeieaton Aof Letters Patent.

ratentedauly es, 1915.

Serial N 647311.

having one endthreaded andscrewed into thefhead 7, and a head 9 ,connected with the lower endoffthe dead-.lever and having a socket Ainto which the end of the rod 8 eX- tends and rotatably retained by means of a screw 10 lextending into an annular groove in the rod.l On the rod 8 adjacent to the head9 is secured a conical clutch-collar 11, and aroundtlie head'is rotatably disposed the clutch-sleeve 12, an annular space 13 being 'formed 'between Athe parts Vwhich may be filledwith a lubricant. The inner end of the clutch-sleeve' fits upon the collar 11: and is engaged a' washer 14 slidably disposed onlthe rod8.' lhewasherA is held in engagementwitlr the' endof the clutch-sleeve by means ofav springldisposed around the rod, and of'which the endopposite the washer engagesacollar 16 secured .upon the rod. The clutch-sleeve', atV the end thereof adjacent to the ylever 3, is providedwith a lug 17` ofwhichj'the endiis beveled vand eX- tends iso as to? be 'infposition to engage one edge ofthe lever 3,".as slrown in Fig. 2. A ting-er 1S is adjustably connected with a lug 19 on th'e clutch-sleeve` an'deXtends alongside the lever, being provided with a laterallyl inclined end portion 20 which presents afb'eveled face for engagement with the edge of Vthe lever 3 opposite the lug 17 The relations ofthe tru'ckelevers tothe bottom-rod connection thereof at applied and release positions of the-brakes are shown in dotted and .full lines, respectively, in the drawings, andjfrom the same itiwillgbe apparent that inthe `mbvingof-the brakesffrom one position to" the other there-is a change in the angular' relation yof the axes of the levers andbottomaod-` The length ofthe finger 18 Ais so adjustedthat there is sufficient clearance between the' lever 3 vandfthe bevel faces of`tlie'ngerlportion 20 and lug 17 to permitthe normal movement of the lever 8, in applying and releasing the brakes, withoutcausing'the clutch-sleeve to be rotated by the `engagement ofthelevcr with said bevel faces. When there is more thanthe normal clearance betweenV the brakeshoes and wheels, eitherfrom wear of'the shoes or in the initi'aladjustingof the'brakes, and lconsequently a greatermovement ofthe levers isrequired in moving from release to applied position, then as the lever 3 moves to appliedposition the same engages the bevel face of the Vlug 17 and causes a certamrotw tion of the clutch-sleeve 12 upon the head 9, in the direction indicated by the arrow in Fig. 2. At the same time the longitudinal pressure upon the clutch-sleeve tends to compress the spring 15 and to loosen the frictional engagement between the sleeve and the collar 11, and the friction between the rod 8 and the heads 7 and 9 is greatly increased by reason of the longitudinal pressure to which the rod is subjected during the application of the brakes. As a. result of the great amount of friction at this time between the rod and heads, and the reduced friction between the clutch members, the clutch-sleeve will slip upon the collar and will not turn the collar and the rod. When the brakes are released the clutch-collar is turned in the opposite direction -by the engagement of the lever with the bevel face of the finger portion 20, and the longitudinal pressure on the sleeve tends to assist the spring 15 in causing friction between the sleeve and the clutch-collar. At the same time the friction between the engaging portions of the rod 8 and the heads 7 and 9 is reduced to a very small amount owing to the lessened stresses in the connection when the brakes are at release position. As a result of the increased friction between the clutch members and the slight friction between the rod 8 and the heads, the rotation of the sleeve causes the clutch-collar and rod to turn with it, and the connection is slightly lengthened by the turning of the threaded part of the rod S in the head 7. The lengthening of the connection, of course, compensates in whole or in part for the wearing of the brake-shoes, and if there remains more than a normal amount-of clearance or slack the same will be compensated for by further lengthening of the connection during subsequent applications and releasings of the brakes. It will be apparent that by the use Of the frictional clutch device in the adjusting connections, the slack of the brakes may be kept almost exactly the same at all times, since the slightest increase of slack over the normal amount will cause rotation of the clutch-sleeve and, no matter how slight may be the movement of the sleeve as the brakes are released, said movement may be lcommunicated to the rod by `the frictional connection.

In the modified form of the adjuster shown in Fig. 3, the head 9 is formed integrally with the rod Sand the head 7 is bored out so as tofit slidably over the threaded portion of the rod. The clutch-collar 11 is threaded internally and is screwed upon the threaded part of the rod 8 to form an abutment against which'the end of the head 7 bears. The sleeve 12 fits rotatably upon the head 7 and is provided with a cap 21 between which and f the clutch-collar is placed a spring 15. At the end of the sleeve l2 adjoining the lever 4 are the lugs 17 and 19 between which is extendedthe arm of a bell-crank 22 which is fulcrumed on the pin 23 which connects the lever 1 and head 7. T he other arm of the bell-crank extends upwardly and is, in effect, forked so as to straddle the pin 24C which connects the lever 4 with the brake-beam clevis. One side of the forked end of the leveris formed by a finger 25 which'is adjustably connected with the body of the lever so that the spacebetween the forks may be varied. The said space is so adjusted that more than a normal movement of the lever must occur before the bell-crank will be movedV upon its fulcrum. l/Vhen the movement of the lever 4 in applying the brakes is suflicient to cause a movement of the bell-crank said movement of the bell-crank causes the clutch-sleeve to be rotated slightly upon the head 7 in the direction of the arrow in Fig. 3. The amount of friction between the clutch-collar and the threaded part of therod, and between thek end of the clutch-collar and the head 7 is so great during the application of theV brakes that the clutch-sleeve will slip upon the collar and the collar will not be turned upon the rod 8. At the releasing movement of the brakes, however, the friction between the clutch-collar and rod, and between the end of the collar and the head 7 is-so reduced that the friction between the clutch members is suflicient to enable the sleeve to turn the collar upon the rod 8', thuslengthening the connection and compensating for the slack of the brakes. As a means of increasing the friction between the clutch members during the movement of the bellcrank caused by releasing of thebrakes, the side of the bell-crank arm engaging the `lug 19 is beveled as shown, that the movement of the arm in rotating the clutch-sleeve will cause a certain end-thrust upon the sleeve tending to force ittighter upon the clutchcollar. 4 Y

Now, having described my invention, what I claim and desire to secure by Letters Patent is:

1. In a slack adjuster for brake rigging, truck-levers, means connecting said levers, said connecting means including two relatively rotatable threaded parts, a frictional clutch device c for rotating one of said threaded parts vto vary the length ofthe connecting means, the `clutch device having a rotatable member adjoining oneof `the truck-levers, means connecting said rotatable member with the truck-lever so that movement of the lever in applying and releasing the brakes may actua-te said member, and means for varying saidconnecting means to permit normal lmovement of the lever without causing rotation of said membei..`

2. In a `slack adjuster for brake rigging,

Vzo

truck-levers, means connecting the same, the connecting means including two threaded parts relatively rotatable to vary the length of the connection, a rotatable clutch member frictionally connected with one of the threaded parts, and means for rotating said member actuatable by a greater movement of one of the truck-lever than its normal movement in applying and releasing the brakes, said means increasing the friction between the clutch member and the part engaged thereby when the clutch member is actuated by releasing movement of the trucklever.

3. In a slack adjuster for brake rigging, truck-levers, means connecting the same, the connecting means including two threaded parts relatively rotatable to vary the length of the connection, a rotatable clutch member frictionally connected with one of said threaded parts, and means actuated by one of the. truck-levers for rotating the said clutch-member, said means increasing the friction between said clutch member and the part engaged thereby when the clutch member is actuated by releasing movement of the truck-lever and reducing the friction between the clutch member and the part engaged thereby when the clutch member is actuated by applying movement of the truck-lever.

4. In a slack adjuster for brake rigging, truck-levers, means connecting the same, the connecting means including two threaded parts relatively rotatable to vary the length of the connection, a rotatable member frictionally connected with one of said threaded parts, and means actuated by one o-f the truck-levers for rotating said member.

5. In a slack adjuster for brake rigging, truck-levers, means connecting the same, the connecting means including two threaded parts relatively rotatable to vary the length of the connection, one of the threaded parts having a conical part thereon, a rotatable sleeve fitting over the conical part and adapted to frictionally engage the same, and connecting means actuatable by one of the truck-levers for rotating the sleeve, the connecting means being adapted to press the sleeve longitudinally thereof to vary the pressure of the same upon the conical part engaged thereby.

6. Inl a slack adjuster for brake rigging, truck-levers, means connecting the same, the connecting means including two threaded parts relatively rotatable to vary the length of the connection, a rotatable sleeve, means frictionally connecting the sleeve with one of the threaded parts, and means carried by the sleeve and positioned in the path of one of the truck-levers, whereby movement of the lever may rotate the sleeve.

7 In a slack adjuster, a connecting member comprising a plurality of serially arranged relatively rotatable parts, the length of the member being variable by relative rotation of one pair of said parts but not being variable by relative rotation of another pair of said parts, and an oscillating element engaging one of the rotatable parts and constantly tending to move said part with it, said oscillating element moving in opposite directions as the longitudinal stress in the member is increased and decreased.

8. In a brake rigging, brake-levers, a connecting member having heads connected with said brake-levers and an intermediate part movable relatively to the heads to vary the length of the member, an element engaging the intermediate part, means for actuating said element in alternate directions as the brakes are applied and released, and means for causing a friction between the said element and the intermediate part greater than that between the intermediate part and the heads when the brakes are released and less than that between the intermediate nart and the heads when the brakes are appliedl 9. A member connecting moving parts and ha vi-ng heads connected with said moving parts, and an intermediate part between the heads movable relatively thereto to vary the length of the member, an element engaging said intermediate part, means ccnnected with one of the moving parts for actuating said element in alternate directions, and means for causing friction between said element and the intermediate part less than that between the intermediate part and the heads when the moving parts are actuated in one direction and greater than that between the intermediate part and the heads when the moving parts are actuated in the other direction, whereby the movement of said element causes movement of the intermediate part in one direction only.

In testimony whereof I have hereunto subscribed my name in the presence of two witnesses.

CHARLES O. ANDERSON. Witnesses:

M. L. HYDE, A. A. MGCLURE.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents, Washington, D. C. 

